Who is Participating?

Shutdown the Oracle Clusterware stack on all the nodes using command crsctl stop crs as root user.
Backup the entire Oracle Clusterware home.
Execute <CRS_HOME>/install/rootdelete.sh on all nodes
Execute <CRS_HOME>/install/rootdeinstall.sh on the node which is supposed to be the first node
The following commands should return nothing
ps -e | grep -i 'ocs[s]d'
ps -e | grep -i 'cr[s]d.bin'
ps -e | grep -i 'ev[m]d.bin'
Execute <CRS_HOME>/root.sh on first node
After successful root.sh execution on first node Execute root.sh on the rest of the nodes of the cluster
Execute as owner of CRS_HOME (generally oracle) <CRS_HOME>/install/onsconfig add_config hostname1:port hostname2:port

Add listener using netca. This may give errors if the listener.ora contains the entries already. If this is the case, move the listener.ora to /tmp from the $ORACLE_HOME/network/admin or from the $TNS_ADMIN directory if the TNS_ADMIN environmental is defined and then run netca. Add all the listeners that were added earlier.

Add ASM & database resource to the OCR using the appropriate srvctl add database command as the user who owns the ASM & database resource. Please ensure that this is not run as root user
Add Instance, services using approproate srvctl add commands. Please refer to the documentation for the exact commands.
execute cluvfy stage -post crsinst -n node1,node2 ### Please ensure to replace node1,node2 with the node names of the cluster